References:

<HIDE>

[1] Baluška, F., Hasenstein, K.H., 1997. Root cytoskeleton: its role in perception and response to gravity. Planta, 203(s1):S69-S78.

[2] Blancaflor, E., Masson, P.H., 2003. Plant gravitropism. Unraveling the ups and downs of a complex process. Plant Physiol., 133(4):1677-1690.

[3] Boonsirichai, K., Guan, C., Chen, R., Masson, P.H., 2002. Root gravitropism: an experimental tool to investigate basic cellular and molecular processes underlying mechano-sensing and signal transmission in plants. Annu. Rev. Plant Biol., 53(1):421-447.

[4] Caspar, T., Pickard, B., 1989. Gravitropism in a starchless mutant of Arabidopsis: implications for the starch-statolith theory of gravity sensing. Planta, 177(2):185-197.

[5] Chen, R.J., Hilson, P., Sedbrook, J., Rosen, E., Caspar, T., Masson, P., 1998. The Arabidopsis thaliana AGRAVITROPIC1 gene encodes a component of the polar-auxin-transport efflux carrier. Proc. Natl. Acad. Sci. USA, 95(25):15112-15117.

[6] Chen, R.J., Guan, C.H., Boonsirichai, K., Masson, P.H., 2002. Complex physiological and molecular processes underlying root gravitropism. Plant Mol Boil., 49(3/4):305-317.

[7] Hao, Z., Ichii, M., 1999. A mutant RM109 of rice (Oryza sativa L.) exhibiting altered lateral root initiation and gravitropism. Jpn. J. Crop Sci., 68(2):245-252.

[8] Harrison, B., Masson, P., 2008. ARL2, ARG1 and PIN3 define a gravity signal transduction pathway in root statocytes. Plant J., 53(2):380-392.

[9] Hobbie, L.J., 1998. Auxin: molecular genetic approaches in Arabidopsis. Plant Physiol. Biochem., 36(1-2):91-102.

[10] Hobbie, L., Estelle, M., 1995. The axr4 auxin-resistant mutants of Arabidopsis thaliana define a gene important for root gravitropism and lateral root initiation. Plant J., 7(2): 211-220.

[11] Hobbie, L., McGovern, M., Hurwitz, L.R., Pierro, A., Liu, N.Y., Bandyopadhyay, A., Estelle, M., 2000. The axr6 mutants of Arabidopsis thaliana define a gene involved in auxin response and early development. Development, 127(1):23-32.

[12] Jia, L., Zhang, B.T., Mao, C.Z., Li, J.H., Wu, Y.R., Wu, P., Wu, Z.C., 2008. OsCYT-INV1 for alkaline/neutral invertase is involved in root cell development and reproductivity in rice (Oryza sativa L.). Planta, 228(1):51-59.

[13] Kiss, J., Hertel, R., Sack, F., 1989. Amyloplasts are necessary for full gravitropic sensitivity in roots of Arabidopsis thaliana. Planta, 177(2):198-206.

[14] Kiss, J., Guisinger, M., Miller, A., Stackhouse, K., 1997. Reduced gravitropism in hypocotyls of starch-deficient mutants of Arabidopsis. Plant Cell Physiol., 38(5):518-525.

[15] Leyser, H.M., Pickett, F.B., Dharmasiri, S., Estelle, M., 1996. Mutations in the axr3 gene of Arabidopsis result in altered auxin response including ectopic expression from the SAUR-AC1 promoter. Plant J., 10(3):403-413.

[16] Lincoln, C., Britton, J.H., Estelle, M., 1990. Growth and development of the axr1 mutants of Arabidopsis. Plant Cell., 2(11):1071-1080.

[17] Lynch, J., 1995. Root architecture and plant productivity. Plant Physiol., 109(1):7-13.

[18] MacCleery, S., Kiss, J., 1999. Plastid sedimentation kinetics in roots of wild-type and starch-deficient mutants of Arabidopsis. Plant Physiol., 120(1):183-192.

[19] Marchant, A., Bhalerao, R., Casimiro, I., Eklof, J., Casero, P.J., Bennett, M., Sandlberg, G., 2002. AUX1 promotes lateral root formation by facilitating indole-2-acetic distribution between sink and source tissues in the Arabidopsis seedlings. Plant Cell., 14(3):589-597.

[20] Marchant, A., Kargul, J., May, S.T., Muller, P., Delbarre, A., Perrot-Rechenmann, C., Bennett, M., 1999. AUX1 regulates root gravitropism in Arabidopsis by facilitating auxin uptake within root apical tissues. EMBO J., 18(8): 2066-2073.

[21] Morita, M.T., Tasaka, M., 2004. Gravity sensing and signaling. Curr. Opin. Plant Biol., 7(6):712-718.

[22] Perrin, R.M., Young, L.S., Murthyum, N., Harrison, B.R., Wang, Y., Will, J.L., Masson, P.H., 2005. Gravity signal transduction in primary roots. Ann. Bot., 96(5):737-743.

[23] Rubio, G., Walk, T., Ge, Z.Y., Yan, X.L., Liao, H., Lynch, J.P., 2001. Root gravitropism and below-grown competition among neighbouring plants: a modeling approach. Ann. Bot., 88(5):929-940.

[24] Stanga, J.P., Boonsirichai, K., Sedbrook, J.C., Otegui, M.S., Masson, P.H., 2009. A Role for the TOC complex in arabidopsis root gravitropism. Plant Physiol., 149(4): 1896-1905.

[25] Vitha, S., Zhao, L.M., Sack, F.D., 2000. Interaction of root gravitropism and phototropism in Arabidopsis wild-type and starchless mutants. Plant Physiol., 122(2):453-461.

[26] Vitha, S., Yang, M., Sack, F.D., Kiss, J.Z., 2007. Gravitropism in starch-excess mutant of Arabidopsis thaliana. Am. J. Bot., 94(4):590-598.

[27] Wang, H., Taketa, S., Miyao, A., Hirochika, H., Ichii, M., 2006. Isolation of a novel lateral-rootless mutant in rice (Oryza sativa L.) with reduced sensitivity to auxin. Plant Sci., 170(1):70-77.

[28] Wilson, A.K., Pickett, F.B., Turner, J.C., Estelle, M., 1990. A dominant mutation in Arabidopsis confers resistance to auxin, ethylene and abscisic acid. Mol. Gen. Genet., 222(2-3):377-383.

[29] Woodward, A.W., Bartel, B., 2005. Auxin: regulation, action, and interaction. Ann. Bot., 95(5):707-735.

[30] Xu, M., Zhu, L., Shou, H.X., Wu, P., 2005. A PIN1 family gene, OsPIN1, involved in auxin-dependent adventitious root emergence and tillering in rice. Plant Cell Physiol., 46(10):1674-1681.

[31] Yamamoto, M., Yamamoto, K.T., 1998. Differential effects of 1-naphthaleneacetic acid, indole-3-acetic acid and 2,4-dichlorophenoxyacetic acid on the gravitropic response of roots in an auxin-resistant mutant of Arabidopsis, auxl. Plant Cell Physiol., 39(6):660-664.

[32] Yang, X., Lee, S., So, J., Dharmasiri, N., Ge, L., Jensen, C., Hangarter, R., Hobbie, L., Estelle, M., 2004. The IAA1 protein is encoded by AXR5 and is a substrate of SCF^TIR1. Plant J., 40(5):772-782.

[33] Yoshida, S., Forno, D.A., Cock, J.H., Gomez, K.A., 1976. Laboratory Manual for Physiological Studies of Rice, 3rd Ed. The International Rice Research Institute, Manila, the Philippines, p.1-83.